There is known a use control method for mobile phones which prevents wrongful use of a mobile phone using location information of the mobile phone (refer to patent document 1, for example). In the method disclosed in patent document 1, area information of an area where use of a mobile phone is permitted is stored in a memory of the mobile phone. The mobile phone recognizes the current location by obtaining necessary information from a control signal sent and received between a base station apparatus and itself. When the current location is within a use-permitted area, the mobile phone dials a designated line selection number according to user's operation. When the current location is outside the use-permitted area, even if the user operates the mobile phone, it issues a warning without transition to a dialing operation.
Also, in patent document 1, there is described that, when the current location is outside the use-permitted area, use of the entire functions of the mobile phone is forbidden, and, other than that, there is also described that only a receiving function, a telephone book display function and the like are selected individually and made unavailable.
Patent document 1J: apanese Patent. Application Laid-Open No. 2000-165952
In recent years, a notebook computer, a mobile terminal and an external recording medium such as a USB (Universal Serial Bus) memory are widely used due to their high transportability and user-friendliness. However, there is a case where such a notebook computer, a mobile terminal, an external recording medium or the like is stolen or lost, resulting in outflow of confidential information and personal information of a company.
A mobile phone described in patent document 1 can prevent outflow of information because its functions cannot be used when existing outside a use-permitted area.
However, a user uses a large variety of files. In a mobile phone described in the patent document 1, when a user is outside a use-permitted area, any files cannot be used any more. However, even if it is outside the use-permitted area, it is desirable to be permitted to use files which are permissible to be used.
In patent document 1, there is also described that, when a mobile phone exists outside a use-permitted area, only an individual function such as a receiving function, a telephone book display function or the like is selected and forbidden to be used. Thus, even if only a specific function is made unavailable, files related to that function cannot be used any more uniformly. For example, even when only a spreadsheet function of a mobile phone is made unavailable, spreadsheet files become unavailable uniformly. In reality, among the files which become unavailable uniformly, there can be files which are permissible to be used outside the use-permitted area. It is desirable to be permitted to use such files outside a use-permitted area.